Shah P S, Deoshatwar A, Karad S, Mhaske S, Singh A, Bachal R V, Alagarasu K, Padbidri V S, Cecilia D
Dengue/Chikungunya Group, ICMR-National Institute of Virology, Pune, India.
Epidemiology Group, ICMR-National Institute of Virology, Pune, India.
J Vector Borne Dis. 2017 Apr-Jun;54(2):172-176.
BACKGROUND & OBJECTIVES: Dengue is highly prevalent in tropical and subtropical regions. The prevalence of dengue is influenced by number of factors, i.e. host, vector, virus and environmental conditions including urbanization and population density. A cross sectional study was undertaken to determine the seroprevalence of dengue in two selected villages that differed in the level of their urbanization and population density.
Two villages with demographically well-defined populations close to Pune, a metropolitan city of western India, were selected for the study. Age stratified serosurvey was carried out during February to May 2011 in the two villages-a rural village A, located 6 km from the national highway with a population density of 159/km2 ; and an urbanized village B, located along the highway with a population density of 779/km2 . Assuming a low seroposi- tivity of 10%, 702 serum samples were collected from village A. Sample size for village B was calculated on the basis of seropositivity obtained in village A, and 153 samples were collected. Serum samples were tested for the presence of dengue virus (DENV)-specific IgG. Simple proportional analyses were used to calculate and compare the seroprevalence.
Of the 702 samples collected from village A, 42.8% were found positive for anti-DENV IgG. A significantly higher seropositivity for DENV (58.8%) was found in village B. In village A, there was an age dependent increase in seroprevalence; whereas, in village B, there was a steep increase from 17% positivity in 0-10 yr age group to 72% in the 11-20 yr age group. The seroprevalence was almost similar in the older age groups.
INTERPRETATION & CONCLUSION: The observations suggested that prevalence of dengue is probably associated with urbanization and host population density. Areas that are in the process of urbanization needs to be monitored for prevalence of dengue and its vector, and appropriate vector control measures may be implemented.
登革热在热带和亚热带地区高度流行。登革热的流行受多种因素影响，即宿主、媒介、病毒以及包括城市化和人口密度在内的环境条件。开展了一项横断面研究，以确定两个城市化水平和人口密度不同的选定村庄的登革热血清流行率。
选择印度西部大都市浦那附近两个人口统计学特征明确的村庄进行研究。2011年2月至5月期间，在这两个村庄进行了年龄分层血清学调查——一个是距离国道6公里、人口密度为每平方公里159人的乡村A；另一个是位于公路沿线、人口密度为每平方公里779人的城市化村庄B。假设血清阳性率较低为10%，从村庄A采集了702份血清样本。根据在村庄A获得的血清阳性率计算村庄B的样本量，共采集了153份样本。检测血清样本中是否存在登革热病毒（DENV）特异性IgG。采用简单比例分析来计算和比较血清流行率。
从村庄A采集的702份样本中，42.8%的抗DENV IgG检测呈阳性。在村庄B中发现DENV的血清阳性率显著更高（58.8%）。在村庄A中，血清流行率随年龄增长而增加；而在村庄B中，从0至10岁年龄组的17%阳性率急剧上升至11至20岁年龄组的72%。老年组的血清流行率几乎相似。
观察结果表明，登革热的流行可能与城市化和宿主人口密度有关。需要对正在城市化的地区监测登革热及其媒介的流行情况，并可实施适当的媒介控制措施。
